I can't remember if it's covered in ODS, but there's actually some pretty simple math that will let you get a workable level shifter just about every time:Take the angle formed by the corner where the shifter is located; then the angle of the shifter itself will always be exactly half of that, i.e. equal to the measure of the angle bisector. The creases will be moved to one side, but the relative angle will be the same.